SP Base Destruction Bug

Game mode: Single Player
Problem: Bug
Region: Jungle/any structure

Upon loading save file, My treehouse jungle base structure fails to calculate anything properly.

Scenario 1: Player walks normally to base after loading a saved game in single player.
Result 1: Base ‘appears’ to render correctly at a distance. Once the player gets closer, sections of the roof immediately crumble due to structural support beams not being calculated. Elevator and all workstations, chests, forges, planters, etc are destroyed, most without loot bags.

Scenario 2: Player has admin powers and teleports directly to the base. (did this for testing purposes)
Result 2: The entire base, including foundations, collapses.

I have a save file available for demonstration purposes, which I can’t upload here. I’m stuck without any recourse to save the structure and my playthrough, and it’s gamebreaking enough that I probably won’t play further. It took a week to put the damn thing together by myself, and lost a weeks worth of resources & thralls.

I’ve uploaded the bugged save file to my google docs here:
game - bugged.db

The base is to the east (should be rendered, but not calculated)

optional tags

This bug occurred while transferring the save file between computers. The original computer had Structure Decay off, while the current one seemed to have the setting enabled. Once structure decay was disabled on the new computer, returning to the base only resulted in portions of the ceiling being destroyed due to structural supports not being calculated. Workstations and other placeables were not affected as they were initially.

With a little admin fixing, I’ve managed to restore my save, but the root problem does need to be addressed, particularly if moving between Decay on/off has immediate and destructive results. I have to play with Decay turned off, as enabling it will cause a LOT of things to spontaneously blow up.